As is known, the semiconductor industry has been trying to develop semiconductor lasers using conventional silicon and/or other Group IV semiconductor manufacturing processes. There has also been significant interest in developing the so-called system on a chip (e.g., SOC), which may include analog and digital circuitry, as well as optical networks, which may all contained in a single package on a single silicon chip. In order to realize an active optical-network-on-a-chip, it has become necessary to provide ultracompact silicon lasers. To make SOCs and other optical semiconductor devices truly practical, it is desirable to have room temperature operation as well as electrical pumping of the silicon laser diodes, which are necessarily contained on the SOCs and/or other optical semiconductor devices.
The search for electrically pumped silicon-based lasers that emit light near 1.3 and 1.55 μm telecomm wavelengths has been underway for years, with a diversity of approaches tried including doping silicon with Erbium ions, or using silicon nano-crystals; however, these as well as other approaches have not provided definitive lasing. The approach closest to success has been the forward-biased silicon PN-junction rib-waveguide device of M. J. Chen et al (“Stimulated emission in a nano-structured silicon pn junction diode using current injection,” Applied Physics Letters, vol. 84, pp. 2163-2166, 22 Mar. 2004). This device exhibited stimulated emission at 1.21 μm, however, no resonator was present, the vertical confinement of light was weak, and the ridge was wide.
It would, therefore, be desirable to overcome the aforesaid and other disadvantages.